Topical antibiotics.
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Anti-Bacterial Agents↗
Biomedical subjects
R Corbett
Publications and source records attributed to R Corbett.
Does lymphangiography have any role in the management of early non-seminomatous germ cell tumours?
Since 1980, 51 patients with non-seminomatous testicular germ cell tumours (NSGCT) and normal or equivocal initial computed tomography (CT) imaging have also had lymphography performed. Radiological records of these patients were reviewed to determine the extent to which lymphography (LAG) contributed to patient management. Forty-nine patients were retrospectively confirmed to have normal CT but of these 14 (29%) were considered to have nodal metastatic disease on lymphography. These patients and seven others with marker only evidence of tumour received chemotherapy and all remain disease-free. Six of thirty-six patients relapsed, but the incidence was not significantly higher in patients who did not undergo LAG (2 of 8:25%) than among those whose initial LAG was normal (4 of 28: 14%). All relapsing tumours achieved a complete remission with chemotherapy. We conclude that although LAG may have resulted in earlier treatment for some patients, several may have been overtreated on the basis of radiological abnormalities which did not represent metastatic disease. We believe that the success of salvage chemotherapy means that LAG may be safely abandoned as a staging procedure for NSGCT.
Humans↗
Preclinical anxiolytic profiles of 7189 and 8319, novel non-competitive NMDA antagonists.
Antagonists at excitatory amino acid receptors, especially the N-methyl-d-aspartate (NMDA) subtype, have been shown to possess anticonvulsant and anxiolytic properties (Clineschmidt et al., 1982; Croucher et al., 1982; Bennett and Amrick, 1986). 7189 and 8319, two closely related benzeneethanamines, are potential novel anxiolytic agents which bind with high affinity to the NMDA receptor at the non-competitive site and are relatively non-toxic (LD50's-160 mg/kg, ip). 7189 and 8319 showed anxiolytic effects in schedule controlled conflict assays as well as in the social interaction (SI) and elevated plus maze (EPM) procedures in rats. Following intraperitoneal administration of 7189 at 20 to 60 mg/kg, conflict responding was increased from 2- to 7-fold in the modified Cook and Davidson and Geller conflict paradigms. 8319, at 2.5 to 5 mg/kg, produced a two fold increase in conflict responding. In the non-schedule controlled procedures, 7189 at 20 mg/kg increased SI time by 23% while in the EPM at 10 to 20 mg/kg, open arm exploration time increased by 41 to 77%. Likewise, 8319 at 2.5 and 5 mg/kg increased open arm exploration and SI time by 50 and 37%, respectively. In summary, 7189 and 8319 were efficacious in four behavioral procedures predictive of potential anxiolytic agents. Although these compounds have not been submitted for clinical evaluation, they may represent a new class of beneficial compounds for the treatment of anxiety.
Aniline Compounds↗
Effects of 5-HT1A receptor agonists and NMDA receptor antagonists in the social interaction test and the elevated plus maze.
The effects of several 5-HT1A agonists and excitatory amino acid antagonists were compared to the standard benzodiazepines, diazepam and chlordiazepoxide (CDP) in two assays predictive of anxiolytic activity, the social interaction and elevated plus maze procedures. Indicative of anxiolytic effects the 5-HT1A agonists, buspirone, gepirone and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) all significantly increased social interaction time and open arm exploration time in the social interaction and elevated plus maze procedures, respectively. Likewise, anxiolytic activity in these assays were also produced by the competitive N-methyl-D-aspartate (NMDA) antagonists, 2-amino-5-phosphonovaleric acid (AP-5), 2-amino-7-phosphonoheptanoic acid (AP-7), 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and the non-competitive NMDA antagonist, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) while NMDA produced anxiogenic effects. Furthermore, the anxiolytic effects of these agents were of equal magnitude to the benzodiazepines. These two classes of compounds were differentiated in the yohimbine-induced seizure assay, with the NMDA antagonists dose dependently antagonizing seizures similar to the benzodiazepines while the 5-HT1A agonists were inactive. These results suggest that the 5-HT1A agonists and the NMDA antagonists may be potential non-classical anxiolytic agents with different mechanisms of action.
Animals↗
Clean up varicose vein surgery--use a tourniquet.
A controlled randomised trial has been carried out to ascertain if there are tangible benefits from using a tourniquet when avulsing varicose veins during routine varicose vein surgery. Twenty-six patients have been studied. Twenty limbs were operated on with a tourniquet and 20 limbs without a tourniquet. The mean weight of varices excised was 2.76 g (range 0.51-8.79 g) with a tourniquet and 2.68 g (0.77-11.27 g) without a tourniquet (NS, Wilcoxon's rank sum test). Mean blood loss was 16 ml (0-136 ml) with a tourniquet and 107 ml (16-581 ml) without a tourniquet (P less than 0.01, Wilcoxon's rank sum test). The mean time to complete avulsions was 38 min with a tourniquet and 35 min without a tourniquet (NS, Student's t test). The tangible benefits of a tourniquet are limited to the saving of blood which can amount to 500 ml per leg. Losses could amount to 1 litre in bilateral cases operated upon without tourniquet. The method is simple, provides a clean operating field and should be more widely used.
Clinical Trials as Topic↗
Molested as children: a hidden contribution to substance abuse?
A history of child sexual victimization may be much more prevalent among substance abusers than previously suspected and may be commonly missed if not assessed directly in every patient. The rates of reporting child sexual abuse among inpatient substance abusers were compared before and after the question was routinely asked in a treatment program. Before routine inquiry, 4% of men and 20% of women disclosed such abuse but after routine inquiries began the rates for adult men quadrupled, up to 42% of the teenaged boys reported such abuse, about 75% of adult women admitted such abuse, and 71 to 90% of teenaged girls disclosed histories of child sexual abuse. Unresolved issues from childhood sexual abuse may be a hidden factor underlying much substance abuse and if not treated may lead to rapid relapse.
Adolescent↗
Laser amplification at 18.2 nm in recombining plasma from a laser-irradiated carbon fiber.
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Journal Article↗
Changes in neutral lipids in brain synaptosomes of rats after chronic administration of ethanol.
Rats were chronically treated with ethanol in a liquid milk diet for 21 days so that the animals consumed 10 +/- 1 g/kg ethanol daily. Following decapitation, the cortex and hippocampus were removed and a synaptosomal fraction prepared from the cortex. After chronic administration of ethanol, a significant decrease in the cholesterol esters:cholesterol ratio was found in the cortical synaptosomes and a decrease was found in the linoleate content of the cholesterol esters fraction. The composition of the pool of free fatty acids remained unchanged. These results are in agreement with those previously reported which show that following its chronic administration, ethanol decreases polyunsaturated fatty acid composition of phospholipids in the synaptosomal fraction and increases the saturated and monounsaturated fatty acids in cholesterol esters.
Alcoholism↗
Reduction of the spermatogonial population in rat testes flown on Space Lab-3.
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Animals↗
The effect of high energy (HZE) particle radiation (40Ar) on aging parameters of mouse hippocampus and retina.
Eight month old C57BL6 mice were exposed (head only) to 0.5 rad or 50 rads of Argon particles at the Lawrence Berkeley Radiation Facility, CA. Neuromotor performance was assessed monthly for six months beginning twelve weeks post-irradiation using a "string test". The decline in motor performance was dose-related and none of the animals was able to complete the task after four months of testing. Morphological changes were monitored six and twelve months post-irradiation by light and electron microscopy. The synaptic density in the CA-1 area of the hippocampus decreased six and twelve months after irradiation. The decrease after twelve months was less than after six months. The width of the outer nuclear layer (ONL) of the retina increased with increasing dose. The number of blood vessels between the ONL and the ganglion layer decreased twelve months after irradiation and this area did not show significant accumulation of age pigment.
Aging↗
Effects of carnitine on changes caused by chronic administration of alcohol.
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Alcoholism↗
Comparison of urinary N-acetyl-beta-D-glucosaminidase and urinary fibrin degradation products for diagnosis of rejection after renal transplantation.
A comparison was made of two established tests to see which was the better indicator of rejection after renal transplantation. Daily urine samples were assayed for excretion of N-acetyl-beta-D-glucosaminidase (NAG) and fibrin degradation products (FDP). Twenty-five rejection episodes were studied in 19 patients. Both indicators tended to move in parallel. NAG was more often elevated in rejection, namely in 96% of rejection episodes as against 76% for FDP, FDP had the advantage of fewer false positive results and when it correctly indicated rejection its increase above the baseline was relatively greater than for NAG, NAG and FDP can both provide early warning of rejection. NAG is preferred for its ease of assay. Assays are performed daily and are of practical value in clinical management. The results of assays must be interpreted in conjunction with all relevant information.
Acetylglucosaminidase↗
Response of the seminiferous epithelium of the mouse exposed to low dose high energy (HZE) and electromagnetic radiation.
This study was undertaken to observe the response of a rapidly dividing cell population (spermatogonial) to Helium and Argon ions as compared to x-rays. Low doses (below 100 rads) were used to more nearly simulate radiation encountered during space missions. The methods used proved compatible for both light and electron microscope studies. The average relative biological effectiveness (RBE) for Helium ions is 1, while Argon is twice as effective in killing spermatogonial cells. Part of this mixed population of cells exhibits a higher sensitivity to radiation below 15 rads. Quantitation of the radiation effects by counting the necrotic cells is not feasible because of their rapid removal, therefore all measurements were done using the surviving fraction (S/So) of spermatogonial cells.
Animals↗
Retinal changes in rats flown on Cosmos 936: A cosmic ray experiment.
Ten rats, five centrifuged during flight to simulate gravity and five stationary in flight and experiencing hypogravity, orbited the Earth. No differences were noted between flight-stationary and flight-centrifuged animals, but changes were seen between these two groups and ground controls. Morphological alterations were observed comparable to those in the experiment flown on Cosmos 782 and to the retinal cells exposed to high-energy particles at Berkeley. Affected cells in the outer nuclear layer showed swelling, clearing of cytoplasm, and disruption of the membranes. Tissue channels were again found, similar to those seen on 782. After space flight, preliminary data indicated an increase in cell size in montages of the nuclear layer of both groups of flight animals. This experiment shows that weightlessness and environmental conditions other than cosmic radiation do not contribute to the observed damage of retinal cells.
Animals↗
Histamine H2-receptor antagonists inhibit enzymic histamine degradation in human skin.
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Amodiaquine↗
Cosmic ray effects on the eyes of rats flown on Cosmos No. 782, experimental K-007.
The eyes from six rats were fixed at the recovery site in Russia after they had circled the earth for 19.5 d in a 62.8 degree orbit. The eyes of six more flight rats were fixed 25 d later. These two preparations and eyes exposed to 1000 rad of neon and argon were compared to obtain data on possible radiation effects on the retina. Most of the flight eye tissue was normal; however, necrotic nuclei were found in the outer nuclear layer and channels were located in the outer segment area. Macrophages were seen between the pigment layer and outer segments. Comparison of the Day zero znd 25-d postflight eyes suggested some possible recovery. Light flashes seen by space travelers and damage from cosmic rays appear to arise from two different sites of interaction. The flashes are created by cosmic ray transversal of the outer segments while pathologic change, when it occurs, is quite possibly from interaction with some part of the nucleus. Nevertheless, direct interaction with other cellular components could also occur. Other factors, such as secondaries from spacecraft shielding, may play an important role.
Animals↗
Cellular immune responsiveness in dogs with demodectic mange.
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Aleutian Mink Disease Virus↗
Clozapine but not haloperidol antagonizes an MK-801 discriminative stimulus cue.
The noncompetitive N-methyl-D-aspartate (NMDA) antagonist dizocilpine (MK-801) produced an interoceptive stimulus cue in rats trained to discriminate between MK-801 (0.075 mg/kg) and saline in a two-choice, discrete trial avoidance paradigm. Haloperidol (0.03-0.3 mg/kg) failed to antagonize the discriminative stimulus cue of MK-801, with all rats choosing the MK-801-appropriate choice lever. Higher doses of haloperidol (1.0 mg/kg) produced significant sedation such that the rats were unable to complete all the trials. In contrast, clozapine dose dependently antagoinzed the discriminative stimulus cue produced by MK-801. Clozapine at a dose of 3.0 mg/kg completely antagonized the stimulus cue produced by MK-801. Therefore, the discriminative stimulus cue produced by the noncompetitive NMDA antagonist MK-801 may be useful as an animal model for selecting novel drugs with potential efficacy for treatment-resistant schizophrenia.
Animals↗